<?php

include_once $_SERVER ['DOCUMENT_ROOT'].'/system/modules/pay/lib/cbjpay/common/BytesUtils.php';

/**
 * PHP版DES加解密类
 * 可与java的DES(DESede/CBC/PKCS5Padding)加密方式兼容.
 */
class DesUtils
{
    public function encrypt($input, $key)
    {
        $key = base64_decode($key);

        $key = $this->pad2Length($key, 8);

        $size = mcrypt_get_block_size('des', 'ecb');
        $input = $this->pkcs5_pad($input, $size);
        $td = mcrypt_module_open('des', '', 'ecb', '');
        $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        @mcrypt_generic_init($td, $key, $iv);
        $data = mcrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        $data = base64_encode($data);

        return $data;
    }
    public function decrypt($encrypted, $key)
    {
        $encrypted = base64_decode($encrypted);

        $key = base64_decode($key);

        $key = $this->pad2Length($key, 8);

        $td = mcrypt_module_open('des', '', 'ecb', '');

        // 使用MCRYPT_DES算法,cbc模式
        $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);

        $ks = mcrypt_enc_get_key_size($td);

        @mcrypt_generic_init($td, $key, $iv);
        // 初始处理
        $decrypted = mdecrypt_generic($td, $encrypted);

        // 解密
        mcrypt_generic_deinit($td);
        // 结束
        mcrypt_module_close($td);
        $y = $this->pkcs5_unpad($decrypted);

        return $y;
    }
    public function pad2Length($text, $padlen)
    {
        $len = strlen($text) % $padlen;
        $res = $text;
        $span = $padlen - $len;
        for ($i = 0; $i < $span; ++$i) {
            $res .= chr($span);
        }

        return $res;
    }
    public function pkcs5_pad($text, $blocksize)
    {
        $pad = $blocksize - (strlen($text) % $blocksize);

        return $text.str_repeat(chr($pad), $pad);
    }
    public function pkcs5_unpad($text)
    {
        $pad = ord($text {strlen($text) - 1});
        if ($pad > strlen($text)) {
            return false;
        }
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) {
            return false;
        }

        return substr($text, 0, -1 * $pad);
    }
}
